Definition of "Fool" :

noun: a person who is gullible and easy to take advantage of

noun: a person who lacks good judgment

noun: a professional clown employed to entertain a king or nobleman in the Middle Ages

verb: indulge in horseplay

"The bored children were fooling about."

verb: fool or hoax

"You can't fool me!."

verb: spend frivolously and unwisely

verb: make a fool or dupe of